The downside of Ember (at least the last time I used it, several years ago) is you must do things "the Ember way", which isn't inherently bad, but there's a lot

The downside of Ember (at least the last time I used it, several years ago) is you must do things "the Ember way", which isn't inherently bad, but there's a lot of implicit functionality that "just works" until it doesn't, and can make debugging a painful experience.